Cross standard form : a solution to improve a given controller with H2 or Hoo specifications

This paper introduces in cross standard form (CSF) as a solution to the inverse optimal control problem. That is, the CSF is a canonical standard problem whose unique H1 or H2 optimal controller is a given controller. From the control design point of view, the general idea is to apply the CSF to a given controller in order to set up a standard problem which can be completed to handle frequency domain H2 or H1 specification. The analytical formulation of the CSF proposed in this paper can be applied to reduced-, full- or augmented-order compensators or two-degree of freedom compensations. Numerical and academic examples are given

Picosecond observation of cation-stepwise delayed and cation-triggered photoinduced intramolecular charge transfer in fluorescent cation probes

Time-resolved transient absorption and gain spectra with subpicosecond laser excitation are reported for donor-donor and acceptor-donor stilbene-crowns (in each compound the electron donor group is the 15-aza-5-crown macrocycle, D1). The effect of the calcium cation on the photoinduced intramolecular charge transfer (ICT) rate constants are measured. When the cation is on the donor side of the molecular system (class 1: D1CS-Crown), the photoinduced ICT process is slowed down and goes through several intermediates characterized by a distancing of the cation, while a solvent molecule enters its coordination sphere. When the cation is on the acceptor side (class 2: D1DS-Crown,D1DB-Crown and D1DCS-Crown), the photoinduced ICT process becomes too fast to be measured, even on the picosecond scale

Picosecond observation of cation-stepwise delayed and cation-triggered photoinduced intramolecular charge transfer in fluorescent cation probes

International audienceTime-resolved transient absorption and gain spectra with subpicosecond laser excitation are reported for donor-donor and acceptor-donor stilbene-crowns (in each compound the electron donor group is the 15-aza-5-crown macrocycle, D1). The effect of the calcium cation on the photoinduced intramolecular charge transfer (ICT) rate constants are measured. When the cation is on the donor side of the molecular system (class 1: D1CS-Crown), the photoinduced ICT process is slowed down and goes through several intermediates characterized by a distancing of the cation, while a solvent molecule enters its coordination sphere. When the cation is on the acceptor side (class 2: D1DS-Crown,D1DB-Crown and D1DCS-Crown), the photoinduced ICT process becomes too fast to be measured, even on the picosecond scale

Cation-triggered photoinduced intramolecular charge transfer and fluorescence red-shift in fluorescence probes

We report the synthesis of two new nonpolar fluorescence cation probes (DDS-crown, 5 and DDB-crown, 6) designed from stilbene and 1,4-diphenyl 1,3-butadiene, respectively, by substitution at the two ends with two electron-donor groups (D) (dimethylamino and monoaza-15-crown-5), one of which is able to chelate a cation. The absorption and fluorescence spectra in several solvents of different polarity and the picosecond transient absorption spectra give an estimate of the Intramolecular Charge Transfer (ICT) strength in the excited state. When a cation (Ca2+) is chelated by the macrocycle, the ICT process is increased and the fluorescence is red-shifted. These spectroscopic effects of cation-chelation are enhanced in a third probe (DDCS-crown, 7) derived from DDS-crown by inserting an electron-acceptor (A) group (CN) at the ortho position of the macrocycle in order to increase the ICT

Cation-triggered photoinduced intramolecular charge transfer and fluorescence red-shift in fluorescence probes

We report the synthesis of two new nonpolar fluorescence cation probes (DDS-crown, 5 and DDB-crown, 6) designed from stilbene and 1,4-diphenyl 1,3-butadiene, respectively, by substitution at the two ends with two electron-donor groups (D) (dimethylamino and monoaza-15-crown-5), one of which is able to chelate a cation. The absorption and fluorescence spectra in several solvents of different polarity and the picosecond transient absorption spectra give an estimate of the Intramolecular Charge Transfer (ICT) strength in the excited state. When a cation (Ca2+) is chelated by the macrocycle, the ICT process is increased and the fluorescence is red-shifted. These spectroscopic effects of cation-chelation are enhanced in a third probe (DDCS-crown, 7) derived from DDS-crown by inserting an electron-acceptor (A) group (CN) at the ortho position of the macrocycle in order to increase the ICT